Process and apparatus for chilling printed webs



Dec. 11, 1962 B. OFFEN PROCESS AND APPARATUS FOR CHILLING PRINTED WEBS Filed March 29, 1961 2 Sheets-Sheet 2 CHILL FIG 2 ROLLERS 50 TO pa ggl l e opvesz '2 5 5g 52 DRYER 3 s gl i as 50 &

Fl G. 5

INVENTOR.

Bernard Offen mm 0 w youyall rates lice 3,067,586 PROCESS AND APPARATUS FGR CHILLDIG PRINTED WEES Bernard Often, Chicago, 111., assignor to B. Ofien & Company, Chicago, Ill. Filed Mar. 29, 1961, Ser. No. 99,095 9 Claims. ((11. 62--63) This invention relates to a process and apparatus adapted for the chilling of printed webs, and it relates more particularly to a method and means for cooling the ink on printed paper which has exited from a drier apparatus. 7

In conventional systems, webs are printed and passes through a drier which is heated to temperatures in the order of 300-350 F. The ink when subjected to temperatures in this range becomes plastic, and therefore, upon exiting from the drier, it is necessary to chill the web to temperatures of the order of 100 F. or below. Prior cooling methods have employed refrigerated rolls or the like adapted for the circulation of city water, well water, refrigerated water, or cooling tower water. Difficulties have been experienced, however, in the prior methods due to a lack of efiicient means for allowing for uncontrollable conditions affecting web cooling. For example, where unrefrigerated water is employed, in many instances, the water is too warm to efiect the desired cooling due to warm weather or continued circulation of the water through the rolls. Where refrigerated cooling is employed, there are many instances where the degree of cooling is far beyond the necessary amount, there being no means for control and economical use of the cooling media. This condition results in an obvious waste of energy employed to refrigerate the coolant.

A highly desirable method and apparatus for chilling printed webs would be one which compensates for variations and conditions which effect web cooling. Such a system would be capable of providing the needed cooling effect under any conditions and without a waste of energy.

It is, therefore, an object of this invention to provide a process and apparatus for chilling printed Webs which combines economy and efiiciency.

It is a further object of this invention to provide a method and apparatus for chilling printed webs which eliminates the disadvantage resulting from variations and conditions effecting web cooling and provides means for definite control and economical use of a cooling media.

It is an additional object of this invention to provide a method and apparatus for chilling printed webs which includes novel combinations of refrigerated and unrefrigerated coolant for circulation through a plurality of cooling rolls and which provides a dependable and inexpensive manner for cooling such webs.

These and other objects of this invention will appear hereinafter and for purposes of illustration, but not of limitation, specific embodiments of this invention are shown in the accompanying drawings, in which FIGURE 1 is a flow sheet diagram of the circulating system of the present invention;

FIGURE 2 is a schematic side elevation of a possible application of the concepts of this invention to a continuous printing line; and

FIGURE 3 is a detailed view of an alternative cooling system adaptable for use in a continuous operation of the type shown in FIGURE 2.

The present invention broadly consists of a system wherein means including a plurality of cooling rolls are provided for the cooling webs immediately as they exit from the printing and drying, such as of a continuous operation. The cooling rolls include at least and 12, and passes through line 24 to lines 26 and/or v one first roll through which unrefrigerated coolant is circulated and at least one subsequent roll through which refrigerated coolant is circulated. As will be apparent from the following description, such a system is capable of achieving the objects of this invention.

With reference to FIGURE 1, there is shown a plurality of cooling rolls 10, 12 and 14. The rolls 10 and 12 are connected through line 16 to a circulating pump 18 which controls passage of Water from a cooling storage tank 20 and a coolant recirculating cooling tower 22.

A by-pass line 26 is connected to the line 24 and is provided with a temperature control valve 28, the latter having a thermostatic connection 30 within the tank 20. If the temperature within the tank 20 reaches a certain minimum value, as might occur in the wintertime, the valve 28 is automatically opened and coolant is passed directly to the storage tank from the rolls 10 and 12, thus by-passing the tower 22.

As shown in FIGURE 1, the line 32 coming from the pump 18 is adapted to pass coolant into line 34 in addition to the line 16. Line 34 passes to an ice machine condenser 36 connected in series with an ice machine 38 and a water cooler 40. The cooler 40 is connected to the roll 14 by means of a delivery line 42 and a return line 44. The auxiliary circulatory pump 46 is associated with the line 44 to aid in circulating coolant through the roll 14. Return line 47 is provided to maintain circulation between the ice machine condenser 36 and the cooling tower 22.

It will be noted that the valves 31 and 33 are associated with the lines 35 and 37 which interconnect the roll 14 with the line 16 and the line 24. By opening these valves, coolant from line 16 can pass to roll 14, an arrangement which is desirable when it is not necessary to use the full refrigerative value of coolant in line 42. The coolant from line 42 may be partially employed, or the refrigerative system may be completely by-passed by closing valves 43 and 45 located in lines 42 and 44, respectively.

The construction in FIGURE 2 illustrates adaptation of the circulatory system of this invention to a continuous printing line. As shown, a roll 48 of web material 50 is unwound and passed through a printing press 52 to a drier 54. The web 50 then passes to cooling rolls 10, 12 and 14 to which a circulatory system of the type shown in FIGURE 1 is connected. It will be noted that the rollers 10, 12 and 14 are arranged in such a fashion that maximum surface contact between the web and rolls is achieved.

The embodiment of this invention, shown in FIGURE 3, illustrates an apparatus having only two cooling rolls 10 and 14 to which a circulatory system of the type shown in FIGURE 1 is adapted to be connected. As will be obvious from the following description of the operation, the inventive principles are applicable to systems with various numbers of cooling rolls.

The operation of this invention may be described as follows. Coolant, which is preferably water, is pumped from cooling tower 22 and tank 20 by means of the pump 18 to the line 32. One portion of the coolant passes through line 16, circulates through the rolls 10 47, thus completing the cycle. A second portion of the coolant in line 32 is continuously circulated through roller 14 while passing through condenser 36, ice machine 38, cooler 40, and the associated delivery and exit lines.

As shown in FIGURES 2 and 3, the web 50 is passed through the printer 52 and drier 54 and then onto the chilled rolls. In FIGURE 2, the web passes first over the rolls 1t} and 12 which are supplied with the cooling tower water. Finally, the web passes over the roll 14 which is supplied with refrigerated water. It will be 3 apparent that the FIGURE 3 construction differs only withrespect .to the elimination of roll 12.

In a typical printing operation, paper in the form of a web is printed with ink and passed to a drier where it isheated between- 390 and 350 F. With the temperature of the cooling tower water in the rolls 1% and 12 as high as100 F., there is nevertheless sufiicient temperature dififerential between the paper and the rolls to cool the paper substantially. For example, paper which contacts the roll It} at a temperature between 300 and 350 F. has been cooled to about 200 F. even with. the relatively hot water in the roll 10. After contact with theroll 12, which also contains the relatively hot water, the paper will cool to approximately 125 F. In order to cool the paper to between about 80 F. and 90 F., apreferred final temperature, refrigerated water passed through the roll 14 is maintained at a temperature of below about .60" F.

The abovedescription illustrates that approximately 83% of the temperature drop from 350 to 85 F. is achieved by means of the unrefrigerated coolant and only 17% was effected by refrigeration. It is. apparent that considerably more energy would be expended in order to achievethe entire drop by refrigeration, and it is clearly apparent that-the amount of chilling would be insufiicient if tower water alonewere employedx'in' all ofthecooling rollss As suggested. by FIGURES [and 3, it is important that substantial surface contact between the rolls and the web be achieved. This is. accomplished by circulating the adjacent rolls, whereby the moving web is wrapped around the roll surfaces.- It will be apparent that the number of rolls may be varied, and generally speaking, fewer rolls can be employed where less severe temperature differentials are'experienced. In this latter connection, where conditions are more severe, refrigerated coolant may be passedthrough two of the latter rolls.

As previously noted, it is apparent that the present invention enables lay-passing of the refrigeration system r.only partial. use of'refrigerated coolant in the roll 1 4.where it is possible to cool the web sufiiciently to obviate the need; for; maximum. cooling effect of the roll 14.

It will be understood that various modifications may bemade in the above disclosed method and apparatus for chilling printed webs without departing from the spirit ofthis invention, particularlyas defined in the following claims.

Iclaim:

1.i In an apparatus for providing printed material on continuouswebs including a printing press and a drier, the improvement comprising means for cooling said web after exit from said drier, said cooling means including a plurality of cooling rolls having internal coolant passages adapted to transport said webs, refrigerating means connected to at least one of the last cooling rolls over which said web is to be transported, said refrigerating means being adapted to. circulate refrigerated coolant through the passages in said' last rolls, means for holding unrefrigerated coolant and means for" circulating said unrefrigerated coolant between said holding means and through thepassages of the other of said cooling rolls.

2. An apparatus according to. claim 1, wherein said means for holding unrefrigerated coolant includes a cooling tower and a storage tank and said'refrigerating means is connected to. said tower and tank'whereby a portion of the-coolant from said tower and tank is passed to said refrigerating means and through said last roll and another portion of the coolant from said tower and tank is passed through said other rolls.

3. An apparatus according to claim 2, wherein said circulatingsystemis adapted to by-pass said refrigerating means whereby all the circulating coolant passing through said rolls is taken directly from said tower and tank.

4. In an apparatus for providing printed material on continuous webs including a printing press and a drier, the improvement comprising means located immediately adjacent said drier for cooling said webs after exit from said drier, said cooling means including a plurality of cooling rolls with coolant passages located internally thereof adapted to transport said webs and adapted to provide substantial surface contact with said webs, refrigerating means connected to at least one of the last cooling rolls over which said web is to be transported and adapted to circulate refrigerated Water through the passages in said last rolls, means for holding unrefrigerated water and means for circulating said unrefrigerated water between said tank and through the passages in the other of said cooling rolls.

5. in an apparatus for providing printed paper including a printing press for applying inks to said paper and teens for drying the ink on said paper, the improvement comprising cooling means for cooling said paper after exit from said drier, said cooling means including a plurality of cooling rolls having coolant passages located therein.

adapted to transport said webs in successive'fashion, refrigerating means connected to at least one of thelast cooling rolls over'which said web is to be transported, said refrigerating means being adapted to circulate re-' frigerated coolant through the passages in said last rolls, means for holding unrefrigerated coolant and means for circulating said unrefrigerated coolant between said hold-' ing means and through the passages in the other of said cooling rolls.

6. In a method for cooling printed webs subsequent to printing and drying of said webs, the improvement'comprising providing a plurality of cooling rolls with internal coolant passages for cooling said webs immediately after said drying, transporting a printed and dried web over said rolls, circulating unrefrigerated coolant through the passages in the first of said rolls to be contacted by said web after drying and circulating refrigerated coolant through the passages in the latter of said rolls to be contacted by said web.

7. A method according to claim 6, including the steps of providing a cooling tower and a storage tank and refrigerating means connected-t0 said tower and said tank, circulating a portion of the coolant in said tower and said tank through said first rolls and circulating another por tion of said coolant through said latter refrigerating means and the latter of said rolls.

8; A method according to claim 6, wherein said coolant is water.

9. In a method for cooling printed webs subsequent to printing and drying of said webs, the improvement comprising providing a plurality of cooling rolls with internal coolant passages for cooling said webs immediately after said drying, said cooling rolls including at least one first unrefrigerated roll and at least one following refrigerated roll, transporting a printed and dried web over successive ones of said rolls, circulating unrefrigerated coolant through the passages in the first unrefrigerated rolls as they are contacted by said webs after drying, and circulating refrigerated coolant through the passages in the following refrigerated rolls as the webs pass thereover.

References Cited in the file of this patent UNITED STATES P-AT ENT S 31,257 Risley Sept. 27, 1938 2,365,352 Moffitt Dec. 19, 1944- 2,.661,669 Friedrich Dec. 8, 1953 2,858,677 Stone Nov. 4, 1958 

